Atrial Fibrilation & Arrhythmia

Atrial fibrillation (AF) is the most commonly encountered arrhythmia in clinical practice; 2.3 million to 6.1 million Americans had AF in 2010.1,2 Since AF is often asymptomatic and frequently goes clinically undetected, experts speculate that these numbers may underestimate the true burden of this disease.3,4 AF occurs in 4 percent of individuals aged 60+ years but increases to 8-10 percent in those older than 80.5 The incidence and prevalence of this condition are expected to climb as the population ages, and as many as 12 million people will have AF by 2050.1,2,5

AF is one of the most common primary and secondary inpatient diagnoses. Index hospitalizations resulting from AF have increased by 60 percent over the past 20 years6with a concurrent spike in AF-related readmissions.7 This growth is due in part to increasing age of the general population6 and to the association of AF with stroke and heart failure.2

AF increases the risk of stroke five-fold across all age groups,2 and is an underlying cause in up to 20 percent of all strokes.2,8 An individual’s likelihood of stroke attributable to AF increases with age; 1.5 percent of strokes among those 50-59 years and 23.5 percent of strokes among those 80-89 years are directly linked to AF.8,9 AF-related strokes tend to be more severe, disabling and fatal than strokes from other etiologies,10 placing a heavy burden on patients, families and healthcare services.

Heart failure and AF frequently co-exist since they share several antecedent risk factors. Approximately 40 percent of individuals with either heart failure or AF will eventually develop the other condition.11 AF prevalence increases in parallel to the severity of heart failure, ranging from 10-50 percent.12 AF can also precipitate acute heart failure and may facilitate the progression of cardiomyopathy.6

The American College of Cardiology Foundation, American Heart Association and Heart Rhythm Society (ACCF/AHA/HRS) collaborative task force recommends that AF be managed through three non-mutually exclusive methods: rate control, prevention of thromboembolism and correction of abnormal rhythm disturbance.13
Antithrombotic therapy has been shown to be a highly efficacious method for the
prevention of stroke among AF patients (risk reduction = 61 percent, 95 percent CI 47-71 percent).14
Patients with AF should receive antiplatelet or anticoagulant treatment. Antiplatelet therapy may be used in low-risk patients or those with contraindications to anticoagulation, while anticoagulant therapy is the most effective stroke prevention treatment for moderate- to high-risk AF patients. Rate and rhythm control may be achieved through either pharmacological treatment or ablation. Pharmacological treatment is typically the first choice for either rhythm or rate control, with left atrial ablation (for rhythm control) or ablation of the atrioventricular conduction system and permanent pacing (for rate control) as second-line choices.15

Despite the known adverse sequelae of AF, and evidence that at least 25 percent of AF-related strokes are potentially preventable with adherence to evidence-based care,2,15-17 current data indicate that only 50-64 percent of eligible patients with AF receive antithrombotic therapy.17,18

Given the confluence of epidemiology, cost implications, availability of established guidelines and effective treatments, as well as observed variability in hospital clinical practice, AF represents a high-impact target for inpatient quality improvement (QI) initiatives. Optimizing AF care during and after hospital admission episodes will benefit both patients and healthcare delivery systems. Atrial flutter carries a stroke risk analogous to that of AF, and similar anticoagulation strategies for stroke prevention in atrial flutter should be employed by care providers in the inpatient and outpatient environments.19 Although not specifically differentiated in this Guide, both AF and atrial flutter represent significant opportunities for stroke prevention through the practice of evidence-based medicine. For subsequent sections regarding anticoagulation, the “AF” designation refers to both atrial fibrillation and atrial flutter.